title: Site-selective deposition of twinned platinum nanoparticles on TiSi2 nanonets by atomic layer deposition and their oxygen reduction activities.
abstract: For many electrochemical reactions such as oxygen reduction, catalysts are of critical importance, as they are often necessary to reduce reaction overpotentials. To fulfill the promises held by catalysts, a well-defined charge transport pathway is indispensable. Presently, porous carbon is most commonly used for this purpose, the application of which has been recently recognized to be a potential source of concern. To meet this challenge, here we present the development of a catalyst system without the need for carbon. Instead, we focused on a conductive, two-dimensional material of a TiSi2 nanonet, which is also of high surface area. As a proof-of-concept, we grew Pt nanoparticles onto TiSi2 by atomic layer deposition. Surprisingly, the growth exhibited a unique selectivity, with Pt deposited only on the top/bottom surfaces of the nanonets at the nanoscale without mask or patterning. Pt {111} surfaces are preferably exposed as a result of a multiple-twinning effect. The materials showed great promise in catalyzing oxygen reduction reactions, which is one of the key challenges in both fuel cells and metal air batteries.
authors.affiliation: Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Xie
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Yang
authors.forename: Binghong
authors.initials: B
authors.lastname: Han
authors.forename: Yang
authors.initials: Y
authors.lastname: Shao-Horn
authors.forename: Dunwei
authors.initials: D
authors.lastname: Wang
mesh_terms: D003460:Crystallization / Q000379:methods*; D004595:Electroplating / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; C009495:titanium dioxide; D010984:Platinum; D014025:Titanium; D010100:Oxygen